Through-bore spool apparatus

ABSTRACT

A through-bore spool apparatus for use in deploying multiple spoolable media in a bore is disclosed. The through-bore spool apparatus comprises a first spool comprising a first spool axis and a first spoolable medium wound around the first spool axis, and a second spool comprising a second spool axis and a second spoolable medium wound around the second spool axis. The first and second spoolable media are de-spoolable simultaneously from the respective first and second spools during movement of the through-bore spool apparatus along a bore.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/GB2019/050068 which has anInternational filing date of Jan. 10, 2019, which claims priority toIntellectual Property Office Application No. GB 1800373.1, filed Jan.10, 2018, the entire contents of each of which are hereby incorporatedby reference.

FIELD

The present disclosure relates to a through-bore spool apparatus for usein deploying elongate media in a bore.

BACKGROUND

Many industries, such as the oil and gas industry, require thedeployment of elongate media within a bore, for example a wellbore, tofacilitate applications such as communication, sensing and the like.

In some examples it may be desirable to deploy electrical conductors ina bore. Optical fibres may also be deployed in bores, for example tofacilitate sensing operations, such as distributed temperature sensing(DTS), distributed pressure sensing (DPS) and distributed acousticsensing (DAS). Optical fibres may also be used for data communicationto/from a bore. In many wellbore applications the optical fibre isdeployed as an integral component of a completion string, and thus maybe classified as a permanent installation. The costs of including apermanently installed optical fibre system can be significant, and thereare also concerns over the longevity of such permanently installedsystems.

SUMMARY

An aspect of the present disclosure relates to a spool apparatus,comprising:

-   -   a first spool comprising a first spoolable medium; and    -   a second spool comprising a second spoolable medium;    -   wherein the first and second spoolable media are de-spoolable        simultaneously from the respective first and second spools        during movement of the through-bore spool apparatus along a        bore.

An aspect of the present disclosure relates to a through-bore spoolapparatus for use in deploying multiple spoolable media in a bore, thethrough-bore spool apparatus comprising:

-   -   a first spool comprising a first spool axis and a first        spoolable medium wound around the first spool axis; and    -   a second spool comprising a second spool axis and a second        spoolable medium wound around the second spool axis;    -   wherein the first and second spoolable media are de-spoolable        simultaneously from the respective first and second spools        during movement of the through-bore spool apparatus along a        bore.

The through-bore spool apparatus may thus be for use in simultaneouslydeploying multiple spoolable media within a bore while the through-borespool apparatus moves along or traverses the bore. In this respect, theprovision of the first and second spools on the same or common apparatusmay facilitate the simultaneous deployment, and indeed a far moreefficient or improved deployment of multiple spoolable media in a bore.

In some example uses, a portion, such as an end portion, of each of thefirst and second spoolable media may be secured or fixed, for exampleadjacent an entrance to the bore, at a surface location etc., such thatthe spoolable media may become despooled from the respective first andsecond spools as the through-bore spool apparatus traverses the bore.

The through-bore spool apparatus may be configured to traverse the boreby being suitably dimensioned to permit passage along said bore. Thethrough-bore spool apparatus may be configured to traverse the bore byaction of gravity, by pumping, by tractoring and/or the like.

The through-bore spool apparatus may be configured to traverse awellbore. In this respect the through-bore spool apparatus may bedefined as a downhole through-bore spool apparatus. The through-borespool apparatus may be configured to traverse equipment orinfrastructure located within a wellbore.

In some examples the bore may be defined within a pipe or pipeline, suchas a surface pipeline, subsea pipeline, subsurface pipeline and/or thelike.

The first and second spoolable media may be de-spoolable simultaneouslyfrom a common side of the through-bore spool apparatus. In use, thefirst and second spoolable media may extend from a trailing side (i.e.,relative to the direction of travel) of the through-bore spoolapparatus. The first and second spoolable media may extend from a commonor different outlets of the through-bore spool apparatus.

In use, one or both of the first and second spoolable media may extendfrom the respective first and second spools substantially in thedirection of the respective spool axes. One or both of the first andsecond spoolable media may be substantially aligned, once despooled,with a respective one of the first and second spool axes. In such anarrangement, one or both of the first and second spoolable media may bedespooled from an end region of its respective spool.

In use, one or both of the first and second spool axes may be alignedsubstantially parallel with an axis of the bore in which thethrough-bore spool apparatus is deployed. Such parallel alignment maycontribute to minimising the outer dimension (e.g., diameter) of thethrough-bore spool apparatus, which may provide advantages when in usein bores of smaller dimensions (e.g., diameters). In one example, boththe first and second spool axes may be aligned substantially parallelwith an axis of the bore in which the through-bore spool apparatus isdeployed.

In some examples, one or both of the first and second spool axes may benon-parallel with an axis of the bore in which the through-bore spoolapparatus is deployed.

The first and second spools may be arranged such that the first andsecond spool axes are substantially parallel with each other. In thisexample the first and second spool axes may also be substantiallyparallel with an axis of a bore in which the through-bore spoolapparatus is deployed.

In some examples the first and second spools may be arranged such thatthe first and second spool axes are laterally off-set. In some examples,the first and second spools may be arranged at least partiallyside-by-side.

The second spool may be arranged on one axial side of the first spool.This arrangement may assist to minimise the outer dimension (e.g.,diameter) of the apparatus, which may permit increased utilisation ofthe apparatus within smaller bore dimensions (e.g., diameters).

The first and second spools may be arranged such that the first andsecond spool axes are coaxially aligned.

The first and second spools may axially overlap. In examples where thefirst and second spool axes are coaxially aligned, at least a portion ofone of the first and second spools may be received axially within atleast a portion of the other of the first and second spools. That is,the first and second spools may be at least partially axially nestedtogether. In examples where the first and second spool axes arelaterally offset, an axial overlap may be such that the first and secondspools may be arranged, at least partially, side-by-side.

In some examples, the second spoolable medium may extend axially throughthe first spool. Thus, the second spoolable medium may axially extend orpass through the first spool during despooling of the second spoolablemedium from the second spool. Such an arrangement may permit the secondspoolable medium to extend from one side of the first spool to theother. This arrangement may provide a more compact and simpler design,avoiding the requirement to route the second spoolable medium around theouter side of the first spool, although in some examples such outsiderouting may be utilised. Furthermore, this arrangement may assist tomaintain a smaller outer dimension (e.g., diameter) of the through-borespool apparatus. Further, such an arrangement may permit both the firstand second spoolable media to extend from a common side of thethrough-bore spool apparatus, for example as a media bundle. In thisexample the second spoolable medium may be substantially aligned with orextend along the first spool axis. Such an arrangement may be permittedat least in examples where the first and second spool axes aresubstantially coaxially arranged.

The passage of the second spoolable medium axially through the firstspool may permit the first spoolable medium to become spiraled aroundthe second spoolable medium as the first spoolable medium is despooled.

The first spool may define an axial passage to accommodate the secondspoolable medium to pass therethrough. In some examples the axialpassage may circumscribe the first spool axis. In some examples at leasta portion of the axial passage may be generally cylindrical. In someexamples the axial passage may comprise an entry region to receive thesecond spoolable medium into the first axial passage. The entry regionmay function to guide the second spoolable medium to a desiredorientation or path, for example to become substantially aligned withthe first spool axis. In some examples the entry region may accommodatean envelope of movement of the second spoolable medium during despoolingfrom the second spool. The entry region may be tarped, for exampleconical. The entry region may be generally funnel shaped. In thisrespect the entry region may comprise a conical section whichtransitions to a substantially cylindrical section.

In some examples the first and second spools may be similarlyconstructed. Alternatively, the first and second spools may bedifferently constructed.

The through-bore spool apparatus may comprise a third spool comprising athird spool axis and a third spoolable medium wound around the thirdspool axis. In some examples the third spool may be configured similarlyto at least one of the first and second spools.

The third spool axis may be arranged to be substantially parallel withat least one of the first and second spool axes.

The third spool axis may be arranged to be laterally off-set form atleast one of the first and second spool axes.

The third spool may be arranged on one axial side of the second spool.The second and third spools may be arranged such that the second andthird spool axes are coaxially aligned.

In some examples, the third spoolable medium may extend axially throughthe second spool.

In one example the first, second and third spools may be axiallyarranged, for example with the second spool axially interposed betweenthe first and third spools. In this example the third spoolable mediummay extend axially through the second spool, and the second and thirdspoolable media may extend axially through the first spool. Such anarrangement may permit the first, second and third spoolable media toextend from a common side of the through-bore spool apparatus, forexample as a media bundle.

The through-bore spool apparatus may comprise further spools withfurther spoolable media, arranged similarly as described above.

In some examples the first and second spoolable media may form or definea media bundle which extends from the through-bore spool apparatus, forexample from a common outlet of the through-bore spool apparatus. Theprovision of a media bundle may exhibit improved strength and/ordurability relative to an individual spoolable medium, thus providingadvantages during and/or subsequent to deployment in the bore.

The media bundle may be formed following despooling of the first andsecond spoolable media from the respective first and second spools andprior to exit of the first and second spoolable media from thethrough-bore spool apparatus. The media bundle may be provided by thefirst and second spoolable media being arranged in close proximity toeach other. The media bundle may be provided by the first and secondspoolable media being in intimate contact. The media bundle may beformed by adhesion of the first and second spoolable media together. Themedia bundle may be provided by an intertwining of the first and secondspoolable media. Such intertwining may be achieved by one of the firstand second spoolable media being spiraled or twisted around the other ofthe first and second spoolable media. Such spiraling or twisting may beachieved by the nature of despooling of at least one of the first andsecond spoolable media.

The through-bore spool apparatus may comprise an outlet, wherein atleast one of the first and second spoolable media extends from theoutlet. The outlet may define an exit passage to accommodate the passageof at least one of the first and second spoolable media therethrough. Insome examples at least a portion of the exit passage may be generallycylindrical. In some examples the exit passage may comprise an accessregion to receive at least one of the first and second spoolable mediainto the exit passage. The access region may guide at least one of thefirst and second spoolable media into a desired position for exiting thethrough-bore spool apparatus. The access region may be tapered, forexample conical. The access region may be generally funnel shaped. Inthis respect the exit passage may comprise a conical section whichtransitions to a substantially cylindrical section.

In some examples the exit passage may contain a material which coats atleast one of the first and second spoolable media during exiting fromthe through-bore spool apparatus. Such a coating may be a protectivecoating, adhesive coating, lubricating coating and/or the like. In someexamples the coating may comprise a liquid, gel, highly viscousmaterial, shear thinning fluid, shear thickening fluid, grease and/orthe like.

The outlet may comprise an arrangement to resist passage of at least oneof the first and second spoolable media therethrough. Such anarrangement may assist to provide a degree of control of movement of thethrough-bore spool apparatus through a bore. In some examples such anarrangement may apply a degree of tension in at least one of the firstand second spoolable media, which may be desirable in some applications.

The through-bore spool apparatus may comprise a single outlet, whereinthe first and second spoolable media extend from the single outlet, forexample as a media bundle.

The through-bore spool apparatus may comprise multiple outlets, whereinthe first and second spoolable media extend from respective outlets.

The first and second spoolable media may comprise any suitable spoolablemedia which may be desirable to be deployed into the bore. The first andsecond spoolable media may be selected to provide a desired functionduring and/or subsequent to deployment. In some examples the first andsecond spoolable media may provide or facilitate the same function. Insome examples the first and second spoolable media may provide orfacilitate different functions. Such different functions may be entirelydiscrete (for example, not associated with each other). However, inother examples, such different functions may be complimentary, andcontribute to the performance of a wider operation (e.g., each spoolablemedium may be used to facilitate different parts or stages of a commonoperation).

At least one of the first and second spoolable media may be used duringand/or subsequent to being deployed within the bore to facilitatecommunication applications, such as the transmission of signals (e.g.,control signals, data etc.). At least one of the first and secondspoolable media may be used during and/or subsequent to being deployedwithin the bore to facilitate sensing applications, such as distributedsensing applications, including one or more of distributed temperaturesensing (DTS), distributed pressure sensing (DPS) and distributedacoustic sensing (DAS). In some examples at least one of the first andsecond spoolable media may be used during and/or subsequent to beingdeployed within the bore to provide a mechanical function, for exampleto provide mechanical strength to (e.g., reinforce) a differentspoolable medium, to carry tensile loading, to facilitate a mechanicalactuation event and/or the like.

The first and second spoolable media may be similar or identical.

The first and second spoolable media may comprise the same kind orspecies of medium, with different characteristics or properties, such asdimensions, composition, construction, conductivity, mechanicalstrength, optical properties, and/or the like.

The first and second spoolable media may comprise different kinds orspecies of medium.

At least one of the first and second spoolable media may comprise anoptical fibre. Such an optical fibre may be used during and/orsubsequent to deployment to facilitate communication applications,sensing applications (e.g., distributed sensing) and/or the like. Atleast one of the first and second spoolable media may comprise a singlemode optical fibre. At least one of the first and second spoolable mediamay comprise a multi-mode optical fibre.

In some examples both the first and second spoolable media may comprisethe same type of optical fibre, for example having the same propertiessuch as dimensions, form, construction, optical properties etc.Alternatively, the first and second spoolable media may comprisedifferent types of optical fibre, for example having differentproperties such as dimensions, form, construction, optical propertiesetc. In some examples the first spoolable medium may comprise a singlemode optical fibre, and the second spoolable medium may comprise amulti-mode optical fibre.

At least one of the first and second spoolable media may comprise anelectrical conductor, such as a metal or metal alloy, for examplecopper.

At least one of the first and second spoolable media may comprise astrength member. The strength member may be configured to accommodate adesired tensile loading. The strength member may be configured toprovide reinforcement, such as strength reinforcement, wearreinforcement and the like to another spoolable medium. In some examplesat least one of the first and second spoolable media may comprise steel,Kevlar, a plastic or other polymer, composite material and/or the like.

In some examples one or both of the first and second spoolable media maybe completely or partially despooled from their respective spools.

The first and second spoolable media may be distinct from each other.That is, the first and second spoolable media may be defined by separatelengths of media, rather than, for example, a single common length. Inthis respect the spoolable media may not be connected to each other, atleast not within the spool apparatus.

In other examples the first and second spoolable media may be defined bya continuous spoolable medium. In such an example a first length of thecontinuous spoolable medium may be wound on the first spool, and asecond length of the continuous spoolable medium may be wound on thesecond spool. In this case the first length of the continuous spoolablemedium may define the first spoolable medium, and the second length ofcontinuous spoolable medium may define the second spoolable medium. Inone example despooling of the continuous spoolable medium may beinitiated simultaneously from its opposing ends. Such an arrangement mayprovide advantages in some applications. For example, some applications,such as communication applications, sensing applications and the likeusing the deployed spoolable medium, may benefit from having moreconvenient access (such as surface access) to the opposing ends of thecontinuous spoolable medium. Furthermore, in some cases effectivelyhaving dual deployed strands (e.g., a loop) of the same spoolable mediummay provide advantages in sensing sensitivity, resolution benefits andthe like.

In some distributed sensing operations providing access to opposite endsof a continuous fibre which is effectively arranged in a “loop”during/after deployment can provide advantages, such as allowing doubleended distributed sensing operations, which may permit improved sensingcapabilities, improved sensitivities, resolution and the like.

The present disclosure may provide advantages in providing the abilityto deploy a “looped” fibre (or other media), without necessarilyutilising multi-core fibres or fibre bundles, which can be moreexpensive.

In some examples the continuous spoolable medium may be completelydespooled from the first and second spools. Alternatively, thecontinuous spoolable medium may be partially despooled.

In some examples the first and second lengths of continuous spoolablemedium may be integrally formed. Alternatively, the first and secondlengths of continuous spoolable medium may be separately formed andconnected together, for example by splicing.

The apparatus may accommodate routing of an interconnected length ofspoolable medium which extends, integrally or otherwise, between thefirst and second spools. Such routing may be provided in a manner toprevent adverse interference with the first and second lengths ofspoolable media during despoiling. Routing of the interconnected lengthof spoolable medium may be accommodated via suitable guide channels,recesses, conduits and/or the like. In some examples such routing maycomprise internally routing the interconnected length of spoolablemedium within the apparatus. Alternatively, at least a portion of theinterconnected length of spoolable medium may extend externally of theapparatus. In such an example protection to the interconnected length ofspoolable medium which extends externally may be provided, for examplein the form of a conduit, shielding etc.

The through-bore spool apparatus may comprise at least one componentcoupled to at least one of the first and second spoolable media. The atleast one component may comprise a temperature sensor, pressure sensor,signal transmitter, signal receiver, light source, light receiver,controller and/or the like.

At least one of the first and second spools may accommodate at least onecomponent coupled to at least one of the first and second spoolablemedia. For example, at least one of the first and second spools maycomprise a pocket or equivalent structure or space to accommodate atleast one component.

At least a portion of one or both of the spoolable media may comprise orbe provided with a coating. The coating may in some examples beconsidered an additional coating. That is to say that the coating may beprovided in addition to any plastic coating, insulation or the like,that may be provided with commercially available bare spoolable media,such as optical fibre. In that regard, the coating may be considered tobe a functional coating, e.g. an additional functional coating for usewhen winding and/or deploying in a bore, or the like.

The coating may be specifically provided in order to assist retainingone or both of the first and second spoolable media within or on theassociated spool. The coating may assist with providing a degree ofresistance to discharge from the through-bore spool apparatus. Thecoating may provide a degree of protection to at least one of the firstand second spoolable media, before, during and/or after discharge fromthe associated spool. The coating may comprise a solid coating, such asa plastic, braided material, Kevlar, PTFE or the like. In some examplesthe coating may comprise a fluidic material, such as a viscous material.The coating may comprise a grease, or other similar non-Newtonian fluid,such as a shear thickening fluid, shear thinning fluid or the like. Thecoating may be considered to be functionally adhesive. The coating mayexhibit an NGLI number of between 000 to 6, for example between 0 and 5,such as between 2 and 4, for example 3. In some examples multipledifferent types of coating may be provided, for example along differentaxial length portions of at least one of the first and second spoolablemedia.

At least one of the first and second spoolable media may be coated witha coating, such as a grease coating, by stripping at least one of thefirst and second spoolable media through a store or bath of the coatingduring discharge. Such a store or bath may be associated with an outletof the through-bore spool apparatus.

At least one of the first and second spoolable media may be coated witha coating prior to being wound on the associated spool. At least one ofthe first and second spoolable media may be coated with a coating duringthe process of winding on the associated spool. For example, the coatingmay be spray deposited on at least one of the first and second spoolablemedia during winding.

In one example at least one of the first and second spools may be coatedwith the coating, such as a grease, prior to winding one of the firstand second spoolable media on the spool. As such, winding the medium onthe spool may cause said medium to become coated.

At least one of the first and second spools may comprise a dischargeregion to improve discharge of the associated spoolable medium from thespool. The discharge region may be provided on one end of the spool, forexample adjacent a winding surface of the spool. The discharge regionmay be provided for uses where the spoolable medium is dischargedgenerally parallel with the associated spool axis. The discharge regionmay assist to lift the spoolable medium from a surface of the spool,such as a winding surface of the spool. This may minimise the effect ofa helix of the spoolable medium during discharge from radially bindingon the spool, which may otherwise provide resistance to discharge,increasing the likelihood of breakage. Furthermore, in some exampleswhere a degree of adhesion may be present between the spoolable mediumand the spool, for example caused by the presence of grease, thedischarge region may assist to break this adhesion.

The discharge region may comprise a geometrical feature, such as anupset portion, annular lip, bump or the like.

At least one of the first and second spools may comprise a store regionfor storing a length of associated spoolable medium, for exampleseparately from a primary wound section of said spoolable medium (forexample separately from wrap segments of the spoolable medium, asdescribed below). Such an arrangement may facilitate ease of access tothe stored length of the spoolable medium.

The store region may facilitate storage of one end region of theassociated spoolable medium. The store region may accommodate at leastone wrap or turn of the end region of the associated spoolable medium.In one example the store region may accommodate one end region of theassociated spoolable medium, before said medium transitions into formingthe primary wound section of said spoolable medium (for example wrapsegments). In this example the stored end may define an initiating endof the spoolable medium. In some examples providing ease of access tothe initiating end region of the spoolable medium, with the terminatingend being easily accessible following winding of the spool, mayfacilitate testing of the spoolable medium while on the spool, forexample permitting transmission of a signal (e.g., optical signal, EMsignal etc.) from one end and reception at the other, to detect anyissues such as breakage and the like.

Providing ease of access to an end of the spoolable medium in the storeregion may permit said end of the medium to be available for connectionto apparatus, such as a sensor, signal source etc.

The store region may be provided adjacent a winding surface of thespool, for example a winding surface of a bobbin. A transition path maybe provided to allow the spoolable medium to extend from the storeregion to the winding surface. The transition path may comprise achannel, recess, bore or the like.

The store region may comprise an annular recess.

At least one of the first and second spools may comprise a bobbin uponwhich the associated spoolable media is wound. The bobbin may define anaxis. The bobbin axis may be aligned with the associated spool axis. Thebobbin axis may define the associated spool axis.

The bobbin may be temporarily provided as part of the spool, for exampleprovided initially to support the associated spoolable medium duringwinding thereon. In this respect once the spoolable medium is suitablywound, the bobbin may be extracted or removed. Such an arrangement maypermit despooling from an interior region of the associated spool, ifrequired. In this example an outer casing or structure may be providedover the wound spoolable medium. The bobbin may comprise a material orcoating, such as a low friction material or coating which may assistremoval. At least a portion of the bobbin may define a variable geometryto facilitate removal. At least a portion of the bobbin may befrangible, meltable or the like.

The bobbin may provide a permanent component of the spool. For example,the bobbin may remain in place such that the associated spoolable mediumis despooled from the bobbin.

The bobbin may comprise or define any cross-section. An outer surface ofat least part of the bobbin may be curved, for example circular. Anouter surface of at least part of the bobbin may be polygonal, regularor irregular. In such an arrangement an outer surface of at least aportion of the bobbin may comprise or define a flat surface.

The bobbin may define a winding surface, upon which winding surface theassociated spoolable medium is wound. At least a portion of the windingsurface may be parallel with the bobbin axis. In some examples this maybe provided by the bobbin comprising a cylindrical portion. The entirewinding surface of the bobbin may be parallel with the bobbin axis.Alternatively, only a portion of the winding surface may be parallelwith the bobbin axis.

At least a portion of the winding surface may be tapered relative to thebobbin axis. The taper may be linear. The taper may be curved. The tapermay be defined by a conical surface of the bobbin. In some examples theentire winding surface may be tapered. Alternatively, only a portion ofthe winding surface may be tapered.

The bobbin may comprise a pocket for accommodating at least oneapparatus or component. The at least one apparatus or component maycomprise a temperature sensor, pressure sensor, signal transmitter,signal receiver, light source, controller and/or the like. The pocketmay be provided in an outer surface of the bobbin. The pocket may beprovided in an end region of the bobbin, for example aligned on thebobbin axis.

In some examples both the first and second spools may comprise a bobbinupon which the associated spoolable media is wound. Each of the firstand second spools may comprise a separate and respective bobbin. In oneexample the separate bobbins may be mounted separately within theapparatus. Alternatively, the separate bobbins may be connected and/ormounted together.

In some examples a single bobbin may be provided which accommodates boththe first and second spoolable media. The single bobbin may beintegrally/unitary formed, or formed in different components andconnected or secured together. The single bobbin may define separatewinding regions to accommodate discrete winding of the first and secondspoolable media thereon. The separate winding regions may be arrangedaxially along a length of the single bobbin.

In some examples providing a single bobbin which accommodates both thefirst and second spoolable media may permit more convenient ability tointerconnect the first and second spoolable media (e.g., to permit“looped” deployment). Such interconnection may comprise a physicalconnection or may be provided by integrally forming the first and secondspoolable media.

The through-bore spool apparatus may comprise a housing, wherein atleast one of the first and second spools is mounted within the housing.The housing may provide a degree of protection to at least one of thefirst and second spools and associated spoolable media. The housing maydefine or include an outlet to permit at least one of the first andsecond spoolable media to exit the housing.

The housing may be generally cylindrical. The housing may be generallyelongate. The housing may define the outer dimensions of thethrough-bore spool apparatus.

The housing may comprise a unitary housing component. Alternatively, thehousing may comprise multiple components coupled together to form thehousing. In some examples, individual housing components may be coupledtogether via at least one of the first and second spools.

In some examples the housing may comprise at least one housing sleeve.An end of the at least one housing sleeve may be received over a portionof at least one of the first and second spools.

The housing may be closed at one end, for examples a trailing end, by anoutlet cap, which outlet cap provides an outlet for at least one of thefirst and second spoolable media.

The housing may be closed at an opposite end, for example a leading end.The opposite end may be closed by a nose cone, for example.

In one example both the first and second spools are mounted within thehousing.

Alternatively, the through-bore spool apparatus may comprise multiplehousings, wherein the first and second spools are mounted in respectivehousings. In this example, individual housings may be secured together.Such individual housings may be arranged side-by-side. Alternatively,such individual housings may be arranged axially relative to each other.

The through-bore spool apparatus may comprise a ballast arrangement, forexample contained within a housing of the apparatus. The ballastarrangement may comprise a weighted material to provide the apparatuswith a desired weight, for example to accommodate gravity deploymentthrough a bore.

The through-bore spool apparatus may define a fish neck, for example topermit connection with a retrieval tool or the like.

At least one (and in some examples both) of the first and secondspoolable media may be wound on a respective spool to form a pluralityof wrap segments arranged axially along the respective spool axis,wherein adjacent wrap segments partially overlap in the axial direction.Each wrap segment may comprise a first wrap layer wound in a first axialdirection over a first axial distance, and a second wrap layer woundover the first wrap layer in a reverse second axial direction over asecond axial distance greater than the first axial distance. Whenarranged as such, the spoolable medium may extend from the second wraplayer of one wrap segment to the first wrap layer of an adjacent wrapsegment.

Accordingly, at least one of the first and second spools may comprise anaxial array of partially overlapping wrap segments each extending alongonly a portion of the axial length of the associated spool. In thisrespect, the total axial length of the spool may be dictated by thenumber of wrap segments arranged along the spool axis and the degree ofoverlap provided between each adjacent segment.

The first wrap layer of one wrap segment may extend in the first axialdirection and over the second wrap layer of a preceding wrap segment.

During despooling, the wrap layers of one segment may be unwound beforebeing unwound from an adjacent wrap segment, and so on. In this way,during despooling the wrap segments may each be sequentially depleted,one after the other, in an axial direction, which may be referenced asthe depleting direction, along the associated spool axis. In thisrespect, during despooling, the axial length of the spool will reduce inthe depleting direction. This contrasts with conventional spoolarrangements in which despooling does not affect the axial spool length(at least until the final layer is reached), with the diameter insteadreducing as individual layers are depleted.

The axial fleeting movement or traverse made by a launch or releasepoint of the spoolable medium during despooling from an individual wraplayer is limited to the axial length of each individual wrap segment,and not, as conventionally known, the entire axial length of the spool,which may otherwise cause complications, such as from the unwoundsection of spoolable medium effectively dragging across and possiblydisturbing the windings still on the associated spool.

Furthermore, the provision of partially overlapping wrap segments may besuch that at least a proportion of one wrap segment is supported orconstrained by the overlapping adjacent segment. Where more than twowrap segments are provided, an intermediate wrap segment may partiallyoverlap an adjacent wrap segment located on one axial side, and bepartially overlapped by an adjacent wrap segment on the opposite axialside. In this way the intermediate wrap segment may firstly providecircumferential support to the underlying portion of the adjacent wrapsegment on one side, while being supported by the overlying portion ofthe adjacent wrap segment on the opposite side. Where the axial overlapis such that there may be axial overlap of one wrap segment withmultiple adjacent wrap segments, the supporting effect may be enhanced.

When multiple, for example more than 3, more than 5, more than 10, morethan 15, more than 30, more than 50, more than 100, more than 150 etc.,wrap segments are provided, the supporting effect by the multipleoverlapping adjacent wrap segments may be such as to provide a robustspool which is resistant to portions becoming prematurely unraveled, orthe like. Further, the multiple adjacent and overlapping segments mayprovide a degree of resistance to being disturbed by any object, such asthe despooled portion of the spoolable medium, dragging thereacross.Also, the supporting effect of the overlapping segments may be such thatany requirement for spool end flanges may be minimised or eliminated.

In some examples a spoolable medium may, in use, be deployed from itsassociated spool to extend in a direction generally parallel to theassociated spool axis. The winding arrangement of the spool may providebenefits in this regard, for example by better accommodating anydragging of the despooled spoolable medium across the spool, orminimising the length of the spool which may be subject to interferenceby the despooled portion. In some examples the deployed spoolable mediummay extend generally parallel and laterally offset from the spool axis.In some examples the deployed spoolable medium may extend generallycoaxial with the spool axis.

In some examples the spoolable medium may, in use, be despooled anddeployed in the depletion direction of the wrap segments. Alternatively,the spoolable medium may, in use, be despooled and deployed in thedirection opposite to the depletion direction of the wrap segments. Inthis example any dragging of the despooled portion across the remainingwraps may be minimised.

The direction in which the spoolable medium is deployed, for exampleaxially deployed, from the associated spool may be in accordance withuser preference, operational requirements and the like. In some examplesa preferred direction of deployment may be determined by the axiallength of the spool. For example, for relatively long spools, there maybe a preference to deploy the spoolable medium in a direction oppositeto the depletion direction of the wrap segments. In this way thedeployed spoolable medium may only ever pass or drag across a singlewrap segment, i.e., the immediate segment form which the spoolablemedium is being deployed. In examples where a shorter spool is provided,it may be more acceptable to deploy the spoolable medium in thedepletion direction of the wrap segments. While the deployed spoolablemedium might drag across the multiple wrap segments, the nature androbustness of the winding arrangement may be such that this isacceptable.

One or more, for example each, wrap segment may comprise one or morewrap layers in addition to the first and second wrap layers. However, insome examples one or more, for example each, wrap segment may compriseonly the first and second wrap layers.

As noted above the second wrap layer may extend over the second axialdistance which is greater than the first axial distance of the firstwrap layer. The additional axial distance covered by the second wraplayer in each wrap segment may facilitate or provide a desired axialspacing of the adjacent wrap segment. In some examples the portion ofthe second wrap layer which extends axially beyond the first wrap layermay function to provide support, for example axial support, to the firstwrap layer. This may restrict or minimise axial slippage or otherwise ofthe first wrap layer. In some examples the portion of the second wraplayer which extends axially beyond the first wrap layer may be referredto or define an anchor portion or anchor winding portion.

The wrap segments, and indeed each of the wrap layers, may includeindividual wraps or turns of spoolable medium which are wrapped at awinding pitch. In this respect the winding pitch may be defined as theangle of an individual wrap with reference to the associated spool axis.A steep winding pitch may define a larger angle relative to the spoolaxis, whereas a shallow winding pitch may define a smaller anglerelative to the spool axis. A steeper winding pitch may provide moreindividual turns or wraps of the spoolable medium per unit axial spoollength, whereas a shallower winding pitch may provide a lower number ofindividual turns or wraps per unit axial spool length. A winding pitchwhich provides adjacent spoolable medium turns or wraps in engagementwith each other may be defined as a closed winding pitch. Adjacentspoolable medium turns or wraps which are axially separated may definean open winding pitch.

In some examples a transition of the spoolable medium from the firstwrap layer to the second wrap layer in one or more, for example each,wrap segment may be provided with a substantially constant windingpitch, albeit with a winding direction change.

A transition of the spoolable medium from the first wrap layer to thesecond wrap layer in one or more, for example each, wrap segment may beprovided with a change in winding pitch. In one example the windingpitch may become shallower once transitioned into the second wrap layer.Such an arrangement may provide the second wrap layer with fewer turnsor wraps of the spoolable medium. During despooling, this may cause thesecond wrap layer to be depleted faster than the first wrap layer, atleast with the same rate of spoolable medium deployment. This mayprovide benefits where the second wrap layer exhibits a reducedself-support capability of individual turns or wraps, in that residencetime of depleting from the second wrap layer is minimised.

In some examples the transition of the spoolable medium from the firstwrap layer into the second wrap layer may be provided with a significantchange, for example reduction, in winding pitch. The transition of thespoolable medium from the first wrap layer into the second wrap layermay be provided with a change from a closed winding pitch to an openwinding pitch.

In one example the first wrap layer of one or more, for example each,wrap segment may comprise a varying winding pitch. For example, thewinding pitch may vary in an axial direction. The first wrap layer ofone or more, for example each, wrap segment may comprise a uniformwinding pitch. For example, the winding pitch may remain constantthroughout the first wrap layer. In some examples the first wrap layermay comprise a closed winding pitch. This may facilitate maximising thelength of spoolable medium which is contained within the first wraplayer.

In one example the second wrap layer of one or more, for example each,wrap segment may comprise a uniform winding pitch. For example, thewinding pitch may remain constant throughout the second wrap layer.

The second wrap layer of one or more, for example each, wrap segment maycomprise a varying winding pitch. For example, the winding pitch mayvary in an axial direction.

In one example a first axial portion of the second wrap layer of one ormore, for example each, wrap segment may comprise a first winding pitchand a second axial portion of the second wrap layer may comprise asecond winding pitch. The first winding pitch may be shallower than thesecond winding pitch. A transition between the first and second axialportions of the second layers may be defined by a change in windingpitch. In one example the second winding pitch may be a closed windingpitch.

In one example the first axial portion may extend over the axial extentof the underlying first wrap layer, and the second axial portion mayextend over the additional axial distance covered by the second wraplayer. In this respect the second axial portion may define an anchorportion or anchor winding portion. The second axial portion may extendover an outer surface of a bobbin.

At least two of the plurality of wrap segments may define a common outermaximum diameter.

The overlapping nature of adjacent wrap segments may result in at leasta portion of one or more of the wrap segments defining or comprising atapered region relative to the spool axis. Such a tapered region mayprovide advantages in permitting one wrap or turn of spoolable mediumwithin a wrap layer providing support or defining an anchor point for anadjacent turn or wrap. This effect may be most prominent in a wrap of atighter winding of the tapered region providing support to an adjacentwrap of a larger radius winding (i.e., on the upslope side).

In one example the first axial direction of winding of the first layerof each segment may be in an upslope direction of a taper. In this way,as individual wraps or turns of the first layer are wound, every tighterwound wrap or turn may provide an anchor for the subsequent turn orwinding on the upslope side. This may not only provide benefits once thespool is completely formed, but also during the winding process of thespoolable medium onto the spool.

At least one of the first and second spools may comprise a bobbinincluding a winding surface. The winding surface may be tapered, whereinthe taper of the winding surface may permit at least portions of one ormore of the wrap segments to define a taper, which may provideadvantages, such as those mentioned above.

One portion of the winding surface of the bobbin may be tapered relativeto a bobbin axis, and an adjacent portion of the winding surface may beparallel relative to the bobbin axis. Winding of the associatedspoolable medium on to the bobbin may be initiated on the taperedportion. For example, winding of the first wrap layer of an initial wrapsegment may be initiated on the tapered portion. This arrangement mayinitiate a taper of each wrap segment. Furthermore, this arrangement mayfacilitate self-support within adjacent wraps or turns of the spoolablemedium in the first layer.

In one example, winding of the first wrap layer of an initial wrapsegment may be initiated at or adjacent a transition region between thetapered and parallel portions of the winding surface.

The first axial direction may be a direction which is in an up-slopingdirection of the tapered portion. This may permit each wrap or turn ofspoolable medium in the first wrap layer to support an adjacent wrap orturn on the upslope side.

At least one of the first and second spools may be non-rotatable, suchthat said at least one spool does not rotate during despooling of theassociated spoolable medium. In this case a launch point of thespoolable medium may orbit the spool. Such orbiting motion may permitone of the first and second spoolable media to be wound around the otherof the first and second spoolable media during despooling.

At least a portion of one or both of the first and second spools may berotatable. At least one of the first and second spools may rotate duringdespooling of the associated spoolable medium therefrom. In one examplerotation of the spool may facilitate a launch point of the spoolablemedium from the spool at a fixed rotational position. In some examplesrotation of the spool may facilitate a launch point of the spoolablemedium from the spool that orbits the spool, but at a lessor rate thanwere the spool to be fixed. In other similar words, rotation of thespool may be used to reduce the speed of orbiting of the launch point,e.g. compared to having a fixed spool. In some examples the spool may bedriven by a rotary drive. Alternatively, a torque may be applied to thespool by the action of the associated spoolable medium despoolingtherefrom. A measurement of rotation of the spool may facilitate thelength of spoolable medium despooled being determined.

At least one of the first and second spools may comprise multiple spoolportions, wherein the associated spoolable medium may extend betweenadjacent spool portions.

At least one of the first and second spools may be mounted in cantileverform within the through-bore spool apparatus. In this respect at leastone of the first and second spools may define a fixed or proximal end,and a free or distal end.

The through-bore spool apparatus may comprise one or more centralisersto facilitate appropriate positioning of the apparatus within a bore.The one or more centralisers may provide central alignment of the spoolapparatus with the bore. Alternatively, the centralisers may provide aneccentric or otherwise off-centre alignment of the spool apparatus withthe bore. In this respect, such an off-centre alignment may beadvantageous in some circumstances, such as to provide a desiredpositioning of the first and second spoolable media within the borefollowing deployment.

Features defined in relation to the through-bore spoolable apparatus arepresented above, with various elements of the spool apparatus definedwhen in use. In this respect, an aspect of the present disclosure alsorelates to a method for deploying multiple spoolable media in a bore,for example using the through-bore spool apparatus. The features definedin relation to the spool apparatus of any other aspect may thus beconsidered described in combination with any method for deployingmultiple media in a bore. For brevity a full repeat of the features arenot presented here.

An aspect of the present disclosure relates to a method for deployingmultiple spoolable media within a bore, comprising:

-   -   locating a through-bore spool apparatus within the bore, wherein        the through-bore spool apparatus comprises a first spool        comprising a first spoolable medium and a second spool        comprising a second spoolable medium; and    -   moving the through-bore spool apparatus through the bore while        simultaneously de-spooling the first and second spoolable media        from the respective first and second spools.

The through-bore spool apparatus may be provided in accordance with anyother aspect, and as such the features defined in relation to any otheraspect are also presented in relation to the method for deployingmultiple spoolable media within a bore.

An aspect of the present disclosure relates to a through-bore spoolapparatus for use in deploying multiple elongate media in a bore, thespool apparatus comprising:

-   -   a first spool comprising a first spool axis and a first elongate        medium wound around the first spool axis;    -   a second spool located on one axial side of the first spool and        comprising a second spool axis and a second elongate medium        wound around the first spool axis;    -   wherein the first and second elongate medium are de-spoolable        simultaneously from the respective first and second spools and        through the outlet of the housing during movement of the spool        apparatus along a bore.

An aspect of the present disclosure relates to a spool apparatus,comprising:

-   -   a first bobbin for supporting a first spoolable medium; and    -   a second bobbin for supporting a second spoolable medium;    -   wherein the through-bore spool apparatus is configured to permit        first and second spoolable media to be de-spoolable        simultaneously from the respective first and second bobbins        during movement of the through-bore spool apparatus along a        bore.

An aspect of the present disclosure relates to a through-bore spoolapparatus for deploying a loop of a spoolable medium within a bore, thethrough-bore spool apparatus comprising:

-   -   a first spool comprising a first length of the spoolable medium        wound thereon, wherein the first length of the spoolable medium        comprises a first end of the spoolable medium; and    -   a second spool comprising a second length of the spoolable        medium thereon, wherein the second length of the spoolable        medium comprises a second end of the spoolable medium;    -   wherein the first and second ends of the spoolable medium are        de-spoolable simultaneously from their respective first and        second spools during movement of the through-bore spool        apparatus along a bore.

An aspect of the present disclosure relates to a method for deploying aloop of a spoolable medium within a bore, comprising:

-   -   locating a through-bore spool apparatus within the bore, wherein        the through-bore spool apparatus comprises:        -   a first spool comprising a first length of the spoolable            medium wound thereon, the first length of the spoolable            medium comprising a first end of the spoolable medium; and        -   a second spool comprising a second length of the spoolable            medium thereon, wherein the second length of the spoolable            medium comprises a second end of the spoolable medium a            second spool comprising a second spoolable medium; and    -   moving the through-bore spool apparatus through the bore while        simultaneously de-spooling the first and second ends of the        spoolable medium from the respective first and second spools.

Features defined in relation to one aspect may be provided incombination with any other aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present disclosure will be described, byway of example only, with reference to the accompanying drawings, inwhich:

FIG. 1 is a diagrammatic illustration of a through-bore spool apparatusin use deploying a media bundle into a bore;

FIG. 2 diagrammatically illustrates the through-bore spool apparatus ofFIG. 1, with the deployed media bundle being located against or inproximity to a bore wall;

FIG. 3 is a perspective view of an example through-bore spool apparatus;

FIG. 4 is a cross-sectional view of the through-bore spool apparatus ofFIG. 3;

FIGS. 5 and 6 are cross-sectional views of different spool bobbins shownremoved from the through-bore spool apparatus of FIG. 3;

FIGS. 7 to 12 diagrammatically illustrate a sequence of winding aspoolable medium on a bobbin to form a spool for use in the through-borespool apparatus of FIG. 3;

FIG. 13 provides a further cross-sectional view of the through-borespool apparatus of FIG. 3, with different spoolable media illustratedduring deployment;

FIG. 14 diagrammatically illustrates the manner of de-spooling of aspoolable medium from a single spool of the apparatus of FIG. 3;

FIG. 15 diagrammatically illustrates an alternative form of bobbin foruse within a through-bore spool apparatus;

FIG. 16 diagrammatically illustrates a portion of the bobbin of FIG. 15with a spoolable medium wound thereon;

FIG. 17 is a cross sectional view of an alternative through-bore spoolapparatus;

FIG. 18 is a diagrammatic illustration of a through-bore spool apparatusin use deploying a loop of an elongate medium in a bore;

FIG. 19 is a cross-sectional view of a portion of a further alternativethrough-bore spool apparatus;

FIG. 20 diagrammatically illustrates a portion of a further alternativethrough-bore spool apparatus;

FIG. 21 is a diagrammatic illustration of an alternative through-borespool apparatus in use deploying multiple spoolable media into a bore;

FIG. 22 is a diagrammatic top elevation of the through-bore spoolapparatus of FIG. 21;

FIG. 23 is a diagrammatic illustration of an alternative form of bobbinfor use within a through-bore spool apparatus;

FIG. 24 illustrates the bobbin of FIG. 23 with a spoolable medium woundthereon;

FIG. 25 is a diagrammatic illustration of an alternative form of bobbinfor use within a through-bore spool apparatus; and

FIG. 26 illustrates the bobbin of FIG. 25 with a spoolable medium woundthereon.

DETAILED DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure relate to a through-bore spoolapparatus capable of traversing a bore such that multiple spoolablemedia (and/or a loop of a continuous spoolable medium) may becomedeployed from the spool apparatus and into the bore. The apparatus maybe used in many applications or environments. For the purposes of thepresent description the apparatus is for use within a wellbore, but itshould be recognised that this is merely exemplary. It should beunderstood that the drawings presented are not provided to scale, andmay not reflect actual dimensions, ratios, angles, number of featuresand the like.

FIG. 1 is a diagrammatic illustration of a through-bore spool apparatus10 deployed within a wellbore 12. The apparatus 10 includes an elongatehousing 13 which carries first, second and third spools 14, 16, 18including respective first, second and third bobbins 15, 17, 19 withrespective first, second and third spoolable media 20, 22, 24 woundthereon. In the present example the first, second and third spools 14,16, 18 are coaxially arranged within the housing 13, wherein the thirdspoolable medium 24, once despooled, is guided to pass axially throughthe first and second spools 14, 16, and the second spoolable medium 22,once despooled, is guided to pass axially, together with the thirdspoolable medium 24, through the first spool 14. The first, second andthird spoolable media 20, 22, 24 form a media bundle 26 which extendsfrom an outlet 28 located at the trailing end of the apparatus 10. Inuse, an end 30 of the media bundle 26 is fixed, for example at a surfacelocation 32, such that the media bundle 26, comprising the first, secondand third spoolable media 20, 22, 24, becomes deployed within thewellbore 12 as the apparatus 10 traverses the wellbore 12. Suchtraversing of the apparatus 10 through the wellbore 12 may be providedby gravity, pumping, tractoring and/or the like.

The first, second and third spoolable media 20, 22, 24 may comprise anysuitable spoolable media which may be desirable to be deployed into thewellbore 12. The spoolable media 20, 22, 24 may be selected to provide adesired function during and/or subsequent to deployment.

At least one of the spoolable media 20, 22, 24 may be used during and/orsubsequent to deployment to facilitate communication applications, suchas the transmission of signals (e.g., control signals, data etc.)between the apparatus 10 and surface 32. At least one of the spoolablemedia 20, 22, 24 may be used during and/or subsequent to deployment tofacilitate sensing applications within the wellbore 12, such asdistributed sensing applications, including one or more of distributedtemperature sensing (DTS), distributed pressure sensing (DPS) anddistributed acoustic sensing (DAS). At least one of the spoolable mediamay be used during and/or subsequent to deployment to provide amechanical function, for example to provide mechanical strength to(e.g., reinforce) a different spoolable medium, to carry tensileloading, to facilitate a mechanical actuation event and/or the like.

At least one of the spoolable media 20, 22, 24 may comprise an opticalfibre. Such an optical fibre may be used during and/or subsequent todeployment to facilitate communication applications, sensing (e.g.,distributed sensing) applications and/or the like. At least one of thespoolable media 20, 22, 24 may comprise a single mode optical fibre. Atleast one of the spoolable media 20, 22, 24 may comprise a multi-modeoptical fibre.

At least one of the spoolable media 20, 22, 24 may comprise anelectrical conductor.

At least one of the spoolable media 20, 22, 24 may comprise a strengthmember, for example to accommodate a desired tensile loading, to providereinforcement, such as strength reinforcement, wear reinforcement andthe like to another spoolable medium.

In the example illustrated in FIG. 1 the media bundle 26 is shownaligned centrally within the wellbore 12. However, in other examples,such as shown in FIG. 2, the media bundle 26 may be positioned adjacentor in contact with the wall of the wellbore 12. Such an arrangement maybe preferable in some applications, for example to place the mediabundle 26 in a preferred, such as a more protected position within thewellbore 12. In this respect, and although not shown, the apparatus 10may comprise features or means to encourage or bias the media bundle 26towards the wall of the wellbore 12. In some examples the media bundle26 may become secured to the wall of the wellbore 26, for example viamagnets, via an adhesive coating on the media bundle 26 and/or the like.

FIG. 3 provides a perspective view of the through-bore spool apparatus10 of FIG. 1, and illustrates the housing 13 of the apparatus 10 asincluding multiple housing components or sleeves, specifically first tofourth housing sleeves 13 a-d secured together, wherein a portion of thebobbin 19 of the third spool 18 also defines an extended outer portionof the housing 13, interposed between the third and fourth housingsleeves 13 c, 13 d. A lower end of the apparatus 10 includes a leadingend nose cone 34, and the trailing end includes an outlet cap 36 whichincludes the media bundle outlet 28.

A longitudinal cross-sectional view through the spool apparatus 10 isillustrated in FIG. 4, reference to which is now made. For claritypurposes the first, second and third bobbins 15, 17, 19 are illustratedwithout the associated spoolable media wound thereon.

One end of the first housing sleeve 13 a is secured to the outlet cap 36via screws 38, and an opposite end of the first housing sleeve 13 a issecured to the first bobbin 15 via screws 40. One end of the secondhousing sleeve 13 b is secured to the first bobbin 15 via screws 42whereas an opposite end of the second housing sleeve 13 b is secured tothe second bobbin 17 via screws 44. In a similar manner, one end of thethird housing sleeve 13 c is secured to the second bobbin 17 via screws46 whereas an opposite end of the third housing sleeve 13 c is securedto the third bobbin 19 via screws 48. In this respect, the first, secondand third bobbins 15, 17, 19 facilitate interconnection of the housingsleeves 13 a-c, and thus improved modular construction of apparatus 10.

The fourth housing sleeve 13 d extends between the third bobbin 19 andthe end nose cone 34. In this respect the end nose cone 34 is securedagainst an end of the fourth housing sleeve 13 d via a threaded rod 50which is tightened, via a nut 52, against a cavity lid 54. An end of thethreaded rod 50 includes a threaded inset 56 which is threadedly securedwith an internal threaded portion 58 provided in an end of the thirdbobbin 19.

The fourth housing sleeve 13 d, end nose cone 34 and cavity lid 54collectively define a cavity 60 within the apparatus 10, wherein thecavity 60 contains a ballast material 62 to provide a desired weight ofthe apparatus 10, for example to facilitate gravity deployment.

Each bobbin 15, 17, 19 defines a respective bobbin or spool axis 64, 66,68, wherein the bobbins 15, 17, 19 are arranged within the apparatus 10such that the axes 64, 66, 68 are arranged coaxial with each other, andsubstantially parallel with an axis of the wellbore 12 (FIG. 1) in whichthe apparatus 10 is deployed. Such an arrangement may permit theapparatus 10 to accommodate the multiple spools while maintaining aminimum outer diameter of the apparatus 10, which may improve utility ofthe apparatus 10 in bores of smaller diameters.

The outlet cap 36 defines or includes an exit passage 70 whichaccommodates the passage of the media bundle 26 (FIG. 1) towards theoutlet 28. The exit passage 70 is generally funnel shaped and includes aconical portion 70 a which transitions to a cylindrical portion 70 b. Inthis respect the conical portion 70 a functions to guide the mediabundle into alignment with the cylindrical portion 70 b.

In some examples the exit passage 70 may contain a material (not shown)which coats the media bundle during exiting from the apparatus 10. Sucha coating may be a protective coating, adhesive coating, lubricatingcoating and/or the like. In some examples the coating may comprise aliquid, gel, highly viscous material, shear thinning fluid, shearthickening fluid, grease and/or the like.

FIG. 5 provides a cross-sectional view of the first bobbin 15 removedfrom the apparatus 10. In the present example the first and secondbobbins 15, 17 are identically formed, and as such the presentdescription with reference to FIG. 5 equally applies to the secondbobbin 17.

The first bobbin 15 includes a proximal end region 72 and a distal endregion 74, wherein the proximal end region 72 is configured to beengaged and connected to the first and second housing sleeves 13 a, 13 b(see FIG. 4), such that the distal end region 74 extends in cantileverform from the proximal end region 72. The proximal end region 72includes an annular lip 76 which provides abutment on opposing sidesthereof with the first and second housing sleeves 13 a, 13 b (see FIG.4). The proximal end region 72 also includes seal grooves 78 foraccommodating seals (not shown) for sealing engagement with therespective first and second housing sleeves 13 a, 13 b, and also anumber of screw holes 80 to facilitate screwed connection to therespective first and second housing sleeves 13 a, 13 b.

The distal end region 74 includes a winding surface 82 whichaccommodates winding of the first spoolable medium 20 (see FIG. 1)thereon, such that the first spoolable medium 20 is wound around thebobbin/spool axis 64. In the present example the winding surface 82includes a conical portion 84 and a cylindrical portion 86. An exampleprocess for winding a spoolable medium on the winding surface 82 willprovided later below.

The first bobbin 15 includes a central passage 88 extending axiallytherethrough and circumscribing the first spool axis 64, wherein thecentral passage 88 is configured to accommodate, in this case, axialpassage of the second and third spoolable media 22, 24 (see FIG. 1). Inthe present example the central passage 88 comprises a variable geometryand includes an entry region 90 to receive the second and thirdspoolable media 22, 24 (FIG. 1) into the central passage 88 such thatthe second and third spoolable media become aligned with the first spoolaxis 64. The entry region 90 in the present example is generally funnelshaped, comprising a conical section 90 a which transitions to asubstantially cylindrical section 90 b.

FIG. 6 provides a cross-sectional view of the third bobbin 19 removedfrom the apparatus 10. The third bobbin 19 includes a cylindrical wallportion 92 at a proximal end thereof, wherein the cylindrical wallportion 92 defines an internal cavity 94 within the third bobbin 19. Aswill be described in more detail below, the cavity 94 is configured toaccommodate one or more components, such as a sensor, transmitter,receiver, controller etc. Such components may be used during and/orfollowing deployment of the apparatus within the wellbore 12 (FIG. 1),for example to perform or support sensing operations, communicationoperations and the like. An end of the cylindrical wall portion 92includes the internal threaded portion 58 which, as illustrated in FIG.4, facilitates threaded connection with the threaded insert 56. The sameend of the cylindrical wall portion 92 also includes an axial shoulder97 which provides abutment with the fourth housing sleeve 13 d (see FIG.4).

The third bobbin 19 comprises a distal end region 95 including a windingsurface 96 which accommodates winding of the third spoolable medium 24(see FIG. 1) thereon, such that the third spoolable medium 24 is woundaround the third spool/bobbin axis 68. In a similar manner to the firstand second bobbins 15, 17, the winding surface 96 of the third bobbin 19includes a conical portion 98 and a cylindrical portion 100.

The third bobbin 19 further comprises an intermediate region 102 whichis interposed between the cylindrical wall portion 92 and the distal endregion 95. The intermediate region 102 is configured to be engaged andconnected to the third housing sleeve 13 c (see FIG. 4), such that thedistal end region 95 extends in cantilever form from the intermediateregion 102. The intermediate region 102 includes an axial shoulder 104which provides abutment with the third housing sleeve 13 c (see FIG. 4).The intermediate region 102 also includes a seal groove 106 foraccommodating a seal (not shown) for sealing engagement with the thirdhousing sleeve 13 c, and also a number of screw holes 108 to facilitatescrewed connection to the third housing sleeve 13 c.

The intermediate region 102 also includes an annular recess 110 foraccommodating an end region of the third spoolable medium 24 (FIG. 1)when wound on the third bobbin 19. A first feed-through bore 112 extendsbetween the recess 110 and the winding surface 96 of the third bobbin19, and similarly a second feed-through bore 114 extends between therecess 110 and the cavity 94. The first and second feed-through bores112, 114 may facilitate routing of the third spoolable medium betweenthe cavity 94 (and any components therein) and the winding surface 96.The annular recess 110 may accommodate a number of turns of the thirdspoolable medium, which may be desirable to provide a degree of slack,for example to accommodate splicing or re-splicing of the thirdspoolable medium with any component contained within the cavity 94.

A description of a sequence of winding a length of the first spoolablemedium 20 on the first bobbin 15 will now be described with reference toFIGS. 7 to 12, which each illustrate the distal end region 74 of thefirst bobbin 15, showing the conical and cylindrical portions 84, 86 ofthe winding surface 82, and the bobbin axis 64.

With initial reference to FIG. 7, winding of the first spoolable medium20 is initiated at a winding start point 120 at the interface betweenthe conical portion 84 and cylindrical portion 86 of the winding surface82. The first spoolable medium 20 is then wound in a first axialdirection, indicated by arrow 122, relative to the bobbin axis 64 toform a number of adjacent individual turns or wraps, at a steep windingpitch which provides the adjacent wraps in contact with each other(i.e., a closed winding pitch). In the present case the first axialdirection is such that the first spoolable medium 20 is added to thebobbin 15 in an upslope direction of the conical portion 84, untilreaching point 124, thus defining a first wrap layer 126. By winding inan upslope direction each wrap or turn provides support to thesubsequent wound wrap or turn of the first spoolable medium 20.

As shown in FIG. 8, the first spoolable medium 20 is then wound in areverse second axial direction, illustrated by arrow 128, over the firstwrap layer 126 at a much shallower winding pitch, until reaching point130 where the first spoolable medium 20 is on the cylindrical portion 86of the winding surface 82, adjacent the starting point of the first wraplayer 126. This may form a first portion 132 of a second wrap layer 134.Following this, as shown in FIG. 9, winding of the first spoolablemedium 20 is continued further in the second axial direction,illustrated by arrow 136, to form a second portion 138 of the secondwrap layer 134, until reaching point 140. The second portion 138 of thesecond wrap layer 134 is wound at a steeper winding pitch (in this casea closed winding pitch) relative to the first portion 132 of the secondwrap layer 134. The second portion 138 may function to provide supportto the first wrap layer 126, and as such in some cases the secondportion 138 may be defined as an anchor or anchor winding portion. Thefirst and second wrap layers 126, 134 may form a first wrap segment 142.

Following this, as illustrated in FIG. 10, the first spoolable medium 20is wound again in the first direction, illustrated by arrow 144, overthe first wrap segment 142, at a closed wind pitch until reaching point146 to form a subsequent first layer 148. Next, as illustrated in FIG.11, the first spoolable medium 20 is wound in the direction of arrow150, at a shallower winding pitch over the first layer 148, with thefirst spoolable medium 20 continuing to be wound in the direction ofarrow 154 to complete a second wrap layer 156. The newly formed firstand second wrap layers 148, 156 define a second wrap segment 158 whichaxially overlaps the first wrap segment 142, wherein each wrap segmentextends to a common outer diameter.

The above winding process may be repeated or continued in the samemanner to add further axially overlapping wrap segments, as illustratedin FIG. 12. The winding of the first spoolable medium 20 may becompleted by winding a final wrap layer 160, as illustrated in FIG. 12.

The winding process may be continued until the required length of thefirst spoolable medium 20 has been wound onto the first bobbin 15 toform the complete first spool 14. In some examples between 10 to 10,000meters, and possibly more, of the first spoolable medium 20 may be woundonto the first bobbin 15, perhaps over 2 to 300, and possibly more,axially overlapping wrap segments.

The provision of partially overlapping wrap segments may be such that atleast a proportion of one wrap segment is supported or constrained bythe overlapping adjacent segment. Further, the multiple adjacent andoverlapping segments may provide a degree of resistance to beingdisturbed by any object, such as the despooled portion of the firstspoolable medium 20, dragging thereacross. Also, the supporting effectof the overlapping segments may be such that any requirement for endflanges may be minimised or eliminated.

The winding process described above may also be applied in relation tothe second and third spoolable media 22, 24 on their respective bobbins17, 19. However, in the case of the third spoolable media 24, a numberof wraps of one end thereof may be formed in the annular recess 110and/or routed into the cavity 64 (see FIG. 6).

Reference is now made to FIG. 13 which provides a further longitudinalcross sectional view of the apparatus 10 of FIG. 3, in this case alsoillustrating the first, second and third spoolable media 20, 22, 24wound on the respective first, second and third bobbins 15, 17, 19 toform the respective first, second and third spools 14, 16, 18.

As described above, and now also shown in FIG. 13, the third spoolablemedium 24 is despooled from the third bobbin 19 and passes, in turn,axially through the second and first bobbins 17, 15, whereas the secondspoolable medium 22 is despooled from the second bobbin 17 and passes,together with the third spoolable medium 24, axially through the firstbobbin 15. The first spoolable medium 20 is despooled from the firstbobbin 15 and combines with the second and third spoolable media 22, 24to define of form the media bundle 26 which exits the apparatus 10 viathe outlet 28.

Reference is additionally made to FIG. 14 which shows an end portion ofthe second spool 16, with the second spoolable media 22 in the processof being despooled, and also illustrating the passage of the thirdspoolable medium 24. During despooling the wrap layers of one segmentare unwound before being unwound from an adjacent wrap segment, and soon. In this way, during despooling the wrap segments are eachsequentially depleted, one after the other, in an axial direction, whichmay be referenced as the depleting direction, along the spool axis 66.

The axial fleeting movement or traverse made by a launch or releasepoint 162 of the second spoolable medium 22 during despooling from anindividual wrap layer is limited to the axial length of each individualwrap segment, and not, as conventionally known, the entire axial lengthof the spool, which may otherwise cause complications, such as from theunwound section of medium 22 effectively dragging across and possiblydisturbing the windings still on the spool 16.

In the present example the second bobbin 17 is rotatably fixed withinthe apparatus 10. In such an arrangement the fibre launch point 162 willorbit the spool 16 during despooling, and as such the second spoolablemedium 22 will become spiraled or wound around the third spoolablemedium 24. A similar despooling process may be present in relation tothe first and third spoolable media 20, 24. In this respect, the firstspoolable medium 20 may become spiraled or wrapped around theintertwined second and third spoolable media 22, 24. Such a despoolingprocess may provide a more robust media bundle 26.

Reference is now made to FIG. 15 which illustrates an alternative formof bobbin 170 for use within a through-bore spool apparatus, such asapparatus 10. The bobbin 170 is similar in many respects to any one ofthe first, second and third bobbins 15, 17, 19 described above.

The bobbin 170 includes a winding surface 172 which has a conicalportion 174 and an adjacent cylindrical portion 176 for receivingspoolable medium thereon, wherein the conical portion 174 is locatedtowards a proximal end 178 of the bobbin 170 and the cylindrical portion176 is located towards a distal end 180. The conical portion 174 definesa tapered surface relative to the axis 182 of the bobbin 170, whereasthe cylindrical portion 176 defines a parallel surface relative to thebobbin axis 180.

The bobbin 170 further comprises an annular lip 184 at the distal end180, wherein the annular lip 184 functions to lift a spoolable mediumduring despooling from the winding surface 172 of the bobbin 170. Thismay minimise the effect of a helix of spoolable medium during dischargefrom radially binding against the bobbin 170, which may otherwiseprovide resistance to discharge, increasing the likelihood of mediumbreakage. Furthermore, in some examples where a degree of adhesion maybe present between the spoolable medium and the bobbin 170 for examplecaused by the presence of grease, the lifting effect provided by theannular lip 184 may assist to break this adhesion.

A spoolable medium may be wound on the bobbin 170 in a similar manner asdescribed above in order to produce a spool 186 as illustrated in FIG.16, wherein the spool 186 includes the bobbin 170 and wound spoolablemedium 188.

An alternative through-bore spool apparatus, generally identified byreference numeral 210, is shown in cross-section in FIG. 17. Theapparatus 210 is similar in many respects to apparatus 10, and as suchlike features share like reference numerals, incremented by 200, and forbrevity purposes only the differences will be highlighted. In thisrespect the apparatus 210 only includes two spools, specifically upperand lower spools 216, 218 each including a bobbin 217, 219 with a commonspoolable medium wound thereon. In this example the spoolable medium isdefined by a continuous spoolable medium and includes a first portion222 wound on the first bobbin 217, and a second portion 224 wound on thesecond bobbin 219, with an interconnecting portion, illustrated bydashed line 200 a or dashed line 200 b extending therebetween. In thisrespect dashed line 200 a represents an option to internally route theinterconnecting portion, whereas dashed line 200 b represents an optionto externally route at least part of the interconnecting portion. Whereexternally routing (200 b) is provided, some level of protection, suchas a conduit, shielding etc. may be provided.

In one example despooling of the continuous spoolable medium may beinitiated simultaneously from its opposing ends. Such an arrangement mayprovide advantages in some applications. For example, some applications,such as communication applications, sensing applications and the likeusing the deployed spoolable medium, may benefit from having moreconvenient access (such as surface access) to the opposing ends of thecontinuous spoolable medium. Furthermore, in some cases effectivelyhaving dual deployed strands (e.g., a loop) of the same spoolable mediummay provide advantages in sensing sensitivity, resolution benefits andthe like.

In some examples the first and second lengths of continuous spoolablemedium may be integrally formed. Alternatively, the first and secondlengths of continuous spoolable medium may be separately formed andconnected together, for example by splicing.

FIG. 18 diagrammatically illustrates the through-bore spool apparatus210 of FIG. 17 in use deploying a loop of an elongate medium in awellbore 12. In this respect the opposite ends 201, 202 of thecontinuous spoolable medium (first and second portions 222, 224) aresecured at a surface region 36 such that the first and second portionsof the spoolable medium 222, 224 may be simultaneously deployed as theapparatus 210 traverses the wellbore 12, with the interconnectingportion 200 a/200 b effectively defining a loop 203. It should berecognised that the loop 203 is merely illustrative in FIG. 18, and thatin some examples portions of the medium may remain in a wound state.

In one example the spoolable medium may comprise an optical fibre foruse in a distributed sensing operation (e.g., DTS, DPS, DAS etc.) withinthe wellbore 12. In this respect the ends 201, 202 of the spoolablemedium may be connected to suitable optical equipment 204 at surface.The installation of a loop of fibre in this example may permit improvedsensing operations to be performed, for example by permitting doubleended distributed sensing.

An alternative through-bore spool apparatus, generally identified byreference numeral 310, is shown in cross-section in FIG. 19. Theapparatus 310, which is only partially shown in FIG. 19, is similar inmany respects to apparatus 10, and as such like features share likereference numerals, incremented by 300, and for brevity purposes certaindifferences will be highlighted.

The apparatus 310 includes first and second bobbins 315, 317 eachconfigured to accommodate respective spoolable media 320, 322 woundthereon. In the present example the first and second bobbins 315, 317are arranged to be axially nested together, such that the second bobbin317 at least partially axially extends into the first bobbin 315. Suchan arrangement may assist to reduce the axial length of the device.

In some examples the spoolable media 320, 322 may be interconnected in acontinuous manner, as illustrated by dashed line 200 c. This may permitdeployment of a looped medium, for example in the manner illustrated inFIG. 18.

FIG. 20 diagrammatically illustrates a spool portion 400 which may beused in a further example of a through-bore spool apparatus. The spoolportion 400 includes a bobbin 402 which includes a first winding region404 and an axially spaced second winding region 406. A first length ofelongate medium 408 is wound on the first winding region 404, and asecond length of elongate medium 410 is wound on the second windingregion 406. The respective media lengths 408, 410 may be wound inaccordance with the example sequence of FIGS. 7 to 12. In use, therespective ends 412, 414 of the first and second lengths of elongatemedia 408, 410 may be despooled simultaneously.

In some examples the first and second lengths of spoolable media 408,410 may be distinct and separate from each other. However, in otherexamples, as illustrated, the first and second lengths of spoolablemedia 408, 410 may be interconnected via an interconnection region 416.In this regard, respective connected end regions 418, 420 of the firstand second lengths of spoolable media 408, 410 may be routed internallyof the bobbin 402, although options for external routing may also bepossible.

In the example illustrated separate lengths of spoolable media 408, 410are connected together, for example via a splice connection 422.However, in other examples the lengths of spoolable media 408, 410 maybe integrally formed.

In the present example the bobbin 402 is of unitary construction.However, in other examples the bobbin 402 may be composed of multipleconnected components.

FIG. 21 is a diagrammatic illustration of a further alternativethrough-bore spool apparatus 510 deployed within a wellbore 12, and FIG.22 provides a top elevation view of the apparatus 510. In this examplethe apparatus 510 includes three (although other examples may have moreor less) housing modules 512, 514, 516 which are secured together viabanding 518 or other suitable means. Each housing module 512, 514, 516contains a spool (not illustrated) which carries a respective spoolablemedium 520, 522, 524 which is despooled and exits the respective housing512, 514, 516 to form a media bundle 526 which becomes deployed withinthe wellbore 12. In some examples at least one, some or each of thehousings 512, 514, 516 may comprise multiple spools. For example, atleast one, some or each housing 512, 514, 516 may be provided inaccordance with any of the other example apparatus 10, 210, 310described above, and/or may include any form of spool/bobbinarrangement.

In the examples provided above the bobbins include a winding surfacehaving both conical and cylindrical portions. However, other forms ofbobbin may be provided, an example of which is shown in FIG. 23. In thisrespect the example bobbin 550 includes a winding surface 552 whichincludes only a conical portion 554 with a tapering surface relative tothe bobbin axis 556. A spoolable medium 558 is shown wound on the bobbin550 to form a spool 560 in FIG. 24. In this respect the spoolable medium558 is wound in a similar manner to that described in relation to FIGS.7 to 12, thus forming multiple overlapping wrap segments.

A further alternative bobbin 600 is illustrated in FIG. 25 and includesa winding surface 602 which includes only a cylindrical portion 604 withits surface parallel to the bobbin axis 606. A spoolable medium 608 isshown wound on the bobbin 600 to form a spool 610 in FIG. 26. In thisrespect the spoolable medium 608 is wound in a similar manner to thatdescribed in relation to FIGS. 7 to 12, thus forming multipleoverlapping wrap segments.

It should be understood that the examples provided are merely exemplaryof the present disclosure, and that various modifications may be madethereto.

The invention claimed is:
 1. A through-bore spool apparatus for use indeploying multiple spoolable media in a bore, the through-bore spoolapparatus comprising: a first spool comprising a first spool axis and afirst spoolable medium wound around the first spool axis; and a secondspool comprising a second spool axis and a second spoolable medium woundaround the second spool axis; wherein the first and second spoolablemedia are de-spoolable simultaneously from the respective first andsecond spools during movement of the through-bore spool apparatus alonga bore, and wherein the first and second spoolable media arede-spoolable simultaneously from a common side of the through-bore spoolapparatus.
 2. The through-bore spool apparatus according to claim 1,wherein the second spool is arranged on one axial side of the firstspool.
 3. The through-bore spool apparatus according to claim 1, whereinthe second spoolable medium extends axially through the first spool fromone side of the first spool to the other.
 4. The through-bore spoolapparatus according to claim 1, wherein the first spool defines an axialpassage to accommodate the second spoolable medium to pass therethrough.5. The through-bore spool apparatus according to claim 1, comprising athird spool comprising a third spool axis and a third spoolable mediumwound around the third spool axis, wherein at least one of: the thirdspool is arranged on one axial side of the second spool; the first,second and third spools are axially arranged with the second spoolaxially interposed between the first and third spools; and the thirdspoolable medium extends axially through the second spool, and thesecond and third spoolable media extends axially through the firstspool.
 6. The through-bore spool apparatus according to claim 1, whereinthe first and second spoolable media form a media bundle which extendsfrom the through-bore spool apparatus.
 7. The through-bore spoolapparatus according to claim 1, wherein at least one of the first andsecond spool apparatus is for use in at least one of distributedtemperature sensing (DTS), distributed pressure sensing (DPS) anddistributed acoustic sensing (DAS).
 8. The through-bore spool apparatusaccording claim 1, wherein at least one of the first and secondspoolable media comprises at least one of an optical fibre, anelectrical conductor and a strength member.
 9. The through-bore spoolapparatus according to claim 1, wherein the first and second spoolablemedia are defined by separate lengths of unconnected media.
 10. Thethrough-bore spool apparatus according to claim 1, wherein the first andsecond spoolable media are defined by a continuous spoolable medium,with a first length of the continuous spoolable medium wound on thefirst spool, and a second length of the continuous spoolable medium maybe wound on the second spool.
 11. The through-bore spool apparatusaccording to claim 10, wherein the first and second lengths of thecontinuous spoolable medium are deployable simultaneously to form a loopof elongate medium in the bore.
 12. The through-bore spool apparatusaccording to claim 1, wherein both the first and second spools comprisea bobbin upon which the associated spoolable media is wound.
 13. Thethrough-bore spool apparatus according to claim 12, wherein the firstand second spools comprise respective bobbins.
 14. The through-borespool apparatus according to claim 12, wherein the first and secondspools comprise a single bobbin which accommodates both the first andsecond spoolable media, the single bobbin defining separate windingregions to accommodate discrete winding of the first and secondspoolable media thereon.
 15. The through-bore spool apparatus accordingto claim 1, comprising a housing, wherein at least one of the first andsecond spools is mounted within the housing.
 16. The through-bore spoolapparatus according to claim 1, wherein at least one of the first andsecond spoolable media is wound on a respective spool to form aplurality of wrap segments arranged axially along the respective spoolaxis, wherein adjacent wrap segments partially overlap in the axialdirection.
 17. The through-bore spool apparatus according to claim 16,wherein each wrap segment comprises a first wrap layer wound in a firstaxial direction over a first axial distance, and a second wrap layerwound over the first wrap layer in a reverse second axial direction overa second axial distance greater than the first axial distance, thespoolable medium extending from the second wrap layer of one wrapsegment to the first wrap layer of an adjacent wrap segment.
 18. Amethod for deploying multiple spoolable media within a bore, comprising:locating a through-bore spool apparatus within the bore, wherein thethrough-bore spool apparatus comprises a first spool comprising a firstspoolable medium and a second spool comprising a second spoolablemedium; and moving the through-bore spool apparatus through the borewhile simultaneously de-spooling the first and second spoolable mediafrom the respective first and second spools from a common side of thethrough-bore spool apparatus.
 19. A method for deploying a loop of aspoolable medium within a bore, comprising: locating a through-borespool apparatus within the bore, wherein the through-bore spoolapparatus comprises: a first spool comprising a first length of thespoolable medium wound thereon, the first length of the spoolable mediumcomprising a first end of the spoolable medium; and a second spoolcomprising a second length of the spoolable medium thereon, wherein thesecond length of the spoolable medium comprises a second end of thespoolable medium a second spool; and moving the through-bore spoolapparatus through the bore while simultaneously de-spooling the firstand second ends of the spoolable medium from the respective first andsecond spools from a common side of the through-bore spool apparatus toform a loop.